EXPERTEC Technical Service Bulletins (T88-25)

Publication date: 1987-09-17
Reference number: T88-25

EXPERTEC TECHNICAL SERVICE BULLETINS

TECHNICAL SERVICE BULLETIN

Reference Number(s): T88-25, Date of Issue: 09/17/1987

CODE F41 OR B441 COOLING FAN FAULT INTERMITTENTLY

Model(s): 1985-87 Cadillac DeVille & Fleetwood

1986-87 Cadillac Eldorado & Seville

1987 Cadillac Allante

Bulletin No.: T88-25

Date: September 17, 1987

SERVICE INFORMATION

Some 1985-1987 DeVilles and Fleetwoods may have a condition of an intermittent cooling fan fault light on and a code F41.

Some 1986-1987 Eldorados, Sevilles and Allantes may have a condition of an intermittent "Cooling Fan Fault" message on the CCDIC and a code B441.

If these conditions occur, and the diagnostic tree in the Service Manual does not lead to the cause of this condition, use the following diagnosis.

DIAGNOSIS

Step 1 - Check for the proper fan control module. 1985 DeVilles and Fleetwoods should have a fan module with part number 1632916 imprinted on the black plastic portion of the case. All 1986 and 1987 vehicles should have a fan module part number 1638574 or 1641400.

Step 2 - Check the fan control module ground connection near the starter. A loose or dirty ground connection near the starter may cause a false code F41 or B441 to set.

Step 3 - Check the cooling fan motors for excessive amperage draw. Disconnect the cooling fan module signal connector (circuits 790 and 791). Using an in-line or inductive ammeter with a 50 amp or lower full scale reading, measure the amperage draw of each fan motor while the fans are overridden at full speed. Use of an ammeter with a 50 amp or lower full scale reading will help ensure a reliable amperage reading. Consult the table below to determine if a cooling fan motor is drawing excessive current:

MAXIMUM ACCEPTABLE COOLING FAN DRAW AT ROOM TEMPERATURE

Year	Car Line	Small Cooling Fan	Large Cooling Fan
1985	DeVille & Fleetwood	13 Amps	13 Amps
1986	DeVille, Fleetwood, Eldorado & Seville	13 Amps	13 Amps
1987	DeVille & Fleetwood	8 Amps	14.5 Amps
1987	Eldorado, Seville & Allante	13 Amps	13 Amps

If a cooling fan is found to exceed the maximum acceptable cooling fan draw, it should be replaced.

WARRANTY INFORMATION

For warranty purposes, use:

Labor Operation No.: J3400

Labor Time: 0.3 hour for one fan

0.4 hour for both fans on DeVilles

0.6 hour for both fans on Eldorados & Sevilles